Catheters of the balloon type having long flexible tubing to reach the desired areas are well-known, as shown in U.S. Pat. Nos. 3,448,739; 3,409,015 and 3,923,065. Such prior art devices employ "Y" shaped fittings or branched tubing at the proximal end of the flexible tubing making them inconvenient to handle and bulky. In addition, once inserted and inflated, failure of the balloon due to leaks or bursting could not be detected readily.
The present invention seeks to overcome the difficulties experienced with prior art devices by providing a small coaxial unit at the proximal end of the flexible tubing which is light in weight and easy to use, particularly in such applications as flow directed catheters. The balloon inflating syringe forms the major portion of the coaxial unit which may also contain a visible balloon pressure indicator. Instead of the branched contruction of prior art devices, all connections are made through the end of the body portion of the coaxial unit. The device lends itself to a wide variety of catheter uses.